An optical coupling arrangement is used to inject light or couple light between two optical waveguide end faces; for example between the end face of an optical waveguide fiber composed of a core and cladding, and the opposite end face of a waveguide structure present on a chip. Such coupling arrangements are used, for example, in optical filters that operate according to thc phased array principle. These have an injection face in which light enters at a specific point, the output wavelength of the optical filter depending on the geometric position of the injection point. Optical filters operating according to the phased array principle are used in particular as multiplexers or demultiplexers in the field of optical telecommunications transmission as they have low insertion attenuation and high crosstalk suppression.
German patent application DE 44 22 651.9 describes what is referred to as a phased array filter whose central wavelength is defined by positioning the optical waveguide fiber which injects the light into the chip waveguide structure, and can thus be precisely aligned. This is done by displacing the waveguide end faces in relation to one another.
It has already been proposed to change the position of the end face of the optical waveguide with respect to the injection face of the chip by virtue of the fact that an element with a variable length is fitted with the fiber and the latter is thus displaced in parallel with the direction of expansion of the element with a variable length.
In order to implement optical coupling between an optical waveguide, an optical waveguide fibre or fiber array and an optical element containing active and/or passive elements, the optical waveguides must be held in a defined position with respect to the injection face of the chip and connected to the corresponding waveguide structure. This is usually carried out by directly bonding the fiber ends to the chip. However, in the above mentioned cases, direct bonding or welding of the fiber ends to the chip is not desired as this would change the necessary relative movement between the fiber and the chip.